At3g16590 Antibody is a specialized immunoglobulin designed to target the protein encoded by the AT3G16590 gene in Arabidopsis thaliana (mouse-ear cress). This antibody is critical for studying plant molecular biology, particularly in investigating gene function, protein localization, and signaling pathways in model organisms.
The AT3G16590 gene encodes a kinase with adenine nucleotide alpha hydrolases-like domain-containing protein . While its precise biological role remains under investigation, it is associated with:
Enzymatic activity: Potential involvement in phosphorylation or nucleotide metabolism due to its kinase-like domains .
Regulatory interactions: Identified as a target of the transcription factor WRKY75, which regulates stress-responsive and developmental pathways in plants .
While specific studies using At3g16590 Antibody are not detailed in public databases, its utility aligns with broader applications in plant science:
Antibodies targeting AT3G16590 could help map its subcellular distribution (e.g., cytoplasm, nucleus) during developmental stages or stress responses. For example:
Immunohistochemistry: Detecting protein expression in tissues like leaves, roots, or flowers .
Western Blotting: Quantifying protein abundance under varying experimental conditions (e.g., abiotic stress).
The antibody may facilitate:
Co-IP (Co-Immunoprecipitation): Identifying interacting proteins in Arabidopsis signaling networks .
Gene Knockout Validation: Confirming protein absence in CRISPR-edited mutants.
Sparse Literature: Limited peer-reviewed studies explicitly cite this antibody, reflecting its niche application in plant biology.
Cross-Reactivity Risks: Potential off-target binding requires validation in Arabidopsis homologs or paralogs.
A. WRKY75-AT3G16590 Interaction
AT3G16590 is a transcriptional target of WRKY75, a key regulator of plant defenses and hormone signaling . This connection suggests its role in:
Stress Adaptation: Modulating responses to pathogens or environmental stressors.
Hormone Crosstalk: Interacting with pathways involving abscisic acid (ABA) or salicylic acid (SA).
B. Broader Antibody Use in Plant Biology
Advanced antibody technologies, such as engineered monoclonal antibodies (e.g., pH-dependent "sweeping antibodies"), highlight the potential for similar innovations in plant research . For instance:
Antigen-Sweeping Mechanisms: Enhancing protein clearance efficiency in complex plant matrices.
At3g16590 is one of two homologues of yeast ADA3 (Alteration/Deficiency in Activation) in Arabidopsis thaliana. It functions as a transcriptional adaptor protein involved in the SAGA (Spt-Ada-Gcn5 acetyltransferase) complex that modulates gene expression through histone acetylation. This protein plays a crucial role in flowering regulation and other developmental processes in plants. Understanding At3g16590 function provides valuable insights into plant development, stress responses, and transcriptional regulation mechanisms in plant biology. The ADA3 proteins are part of a highly conserved transcriptional regulatory pathway found across eukaryotes, making them significant for comparative studies of transcriptional control mechanisms .
At3g16590 is often studied alongside other SAGA complex components in Arabidopsis, including GCN5 histone acetyltransferase, ADA2a and ADA2b transcriptional adaptors, and SGF29 genes. Mutations in these related genes have been associated with developmental defects including dwarfism, impaired meristem development, fertility issues, and altered stress responses, suggesting the potential importance of At3g16590 in similar pathways .
When selecting an At3g16590 antibody for research, several critical factors must be evaluated to ensure experimental success:
Target specificity: Confirm that the antibody recognizes At3g16590 specifically without cross-reactivity to related ADA3 homologues or other SAGA complex proteins in Arabidopsis. Sequence alignment and homology analysis should be performed to identify unique epitopes .
Validation data: Review existing validation data including Western blots, immunoprecipitation results, and ChIP validation. The antibody should demonstrate specific binding to At3g16590 with minimal background .
Application compatibility: Verify that the antibody has been validated for your specific application (Western blot, ChIP, immunofluorescence, etc.). Some antibodies perform well in certain applications but poorly in others .
Clone type and format: Consider whether a monoclonal or polyclonal antibody is more appropriate for your research. Monoclonals offer higher specificity, while polyclonals may provide better sensitivity across multiple epitopes .
Host species: Select an antibody raised in a species that avoids cross-reactivity with other antibodies in your experimental system, particularly important for co-localization studies .
The antibody selection process should be guided by thorough understanding of At3g16590's structure, post-translational modifications, and subcellular localization to ensure targeting of the most relevant form of the protein for your research question .
Validating antibody specificity is essential for obtaining reliable results. For At3g16590 antibodies, implement the following validation approaches:
Genetic Controls:
Test the antibody on wild-type and at3g16590 mutant/knockout lines to confirm signal absence in mutants
Include RNAi or CRISPR-edited lines with reduced At3g16590 expression to verify signal reduction
Biochemical Validation:
Perform Western blot analysis to confirm a single band of appropriate molecular weight (check Uniprot database for predicted molecular weight)
Conduct peptide competition assays where the antibody is pre-incubated with the immunizing peptide; this should eliminate specific signals
Execute immunoprecipitation followed by mass spectrometry to confirm pull-down of At3g16590 protein
Cross-Reactivity Assessment:
Test the antibody against recombinant At3g16590 and its paralog/homolog to assess potential cross-reactivity
Include heterologous expression systems (e.g., bacteria or insect cells expressing At3g16590) as positive controls
Document all validation steps methodically in a table format:
Validation Method | Expected Result | Acceptance Criteria |
---|---|---|
Western blot (WT vs. mutant) | Single band at predicted MW in WT, absent in mutant | >90% signal reduction in mutant |
Peptide competition | Signal elimination | >90% signal reduction |
IP-Mass Spec | At3g16590 identification | Top hit with >2 unique peptides |
Immunofluorescence | Nuclear localization | Signal co-localization with nuclear markers |
Thorough validation should be performed for each experimental application and documented before proceeding with experimental studies .
Chromatin immunoprecipitation (ChIP) experiments with At3g16590 antibodies require careful design to identify DNA regions bound by this transcriptional adaptor protein. Follow this methodological approach based on established protocols:
Sample Preparation:
Harvest appropriate tissue (typically 1-2g of leaf tissue or seedlings)
Crosslink protein-DNA interactions using 1% formaldehyde for 10 minutes
Quench the crosslinking reaction with 0.125M glycine
Isolate and purify nuclei using extraction buffers with protease inhibitors
Sonicate chromatin to generate fragments of 200-500bp (optimize sonication conditions)
Immunoprecipitation:
Pre-clear chromatin with protein A/G beads to reduce non-specific binding
Incubate chromatin with At3g16590 antibody (typically 2-5μg) overnight at 4°C
Capture antibody-protein-DNA complexes using protein A/G beads
Perform stringent washing steps to remove non-specific interactions
Elute protein-DNA complexes and reverse crosslinks at 65°C overnight
Controls and Validation:
Include a negative control (no antibody or IgG from the same species)
Include a positive control (histone H3 antibody)
Use At3g16590 knockout/mutant plants as biological negative controls
Confirm enrichment at expected target genes using qPCR before proceeding to sequencing
Data Analysis:
Normalize ChIP-qPCR data to input DNA (typically presented as percent of input)
For histone modification studies, normalize to total H3 to account for nucleosome density
For genome-wide studies (ChIP-seq), include spike-in controls for normalization
This experimental design allows for identification of genomic regions where At3g16590 is involved in transcriptional regulation, which can be further correlated with gene expression or histone modification data .
When conducting immunofluorescence microscopy with At3g16590 antibodies, implementing appropriate controls is critical for obtaining reliable and interpretable results:
Primary Controls:
Genetic controls: Compare wild-type plants with at3g16590 knockout/mutant lines to confirm signal specificity. The mutant should show significant reduction or absence of signal .
Peptide competition: Pre-incubate the antibody with excess immunizing peptide to block specific binding sites. This should substantially reduce or eliminate specific signals while leaving non-specific signals intact.
Antibody omission: Process samples without primary antibody to assess secondary antibody non-specific binding and tissue autofluorescence.
Isotype control: Use an irrelevant antibody of the same isotype, concentration, and host species to identify non-specific binding.
Technical Controls:
Co-localization markers: Include antibodies against known nuclear proteins (e.g., histone H3) to confirm the expected nuclear localization of At3g16590.
Fixation and permeabilization optimization: Test multiple fixation methods (paraformaldehyde, methanol, etc.) and permeabilization conditions to ensure optimal epitope accessibility without artifacts.
Signal amplification validation: If using signal amplification methods, include samples processed without amplification to assess signal-to-noise ratio improvements.
Fluorophore controls: Include single-fluorophore samples when conducting multi-channel imaging to identify and correct for spectral bleed-through.
Analysis Controls:
Quantification standardization: Use identical acquisition parameters across all samples and controls.
Blind analysis: Have images analyzed by researchers blinded to the experimental conditions to prevent confirmation bias.
Technical replicates: Perform staining on multiple sections from the same sample to assess technical variability.
These controls ensure that observed patterns represent genuine At3g16590 localization rather than artifacts or non-specific binding, which is particularly important given the nuclear localization of this transcriptional adaptor protein .
Optimizing protein extraction for At3g16590 detection requires specialized approaches due to its nuclear localization and potential association with chromatin as part of the SAGA complex:
Buffer Composition Optimization:
Nuclear extraction approach: Use a two-step extraction method:
First buffer: 50mM Tris-HCl pH 7.5, 150mM NaCl, 0.1% Triton X-100, 1mM EDTA
Second (nuclear extraction) buffer: 20mM HEPES pH 7.9, 420mM NaCl, 1.5mM MgCl₂, 0.2mM EDTA, 25% glycerol
Detergent selection: Test multiple detergent combinations:
For membrane dissociation: 0.5-1% NP-40 or Triton X-100
For protein-protein interaction preservation: 0.1% NP-40 or 0.05% digitonin
For stringent extraction: 0.1% SDS (use cautiously as it may denature the protein)
Protease and phosphatase inhibitors: Always include a comprehensive mixture:
Extraction Procedure Optimization:
Tissue disruption: Compare mortar and pestle grinding in liquid nitrogen versus bead-based homogenization to determine optimal cell disruption method.
Temperature conditions: Maintain samples at 4°C throughout extraction to minimize protein degradation.
Sonication parameters: Implement brief sonication (3 cycles of 10 seconds) to enhance nuclear lysis and protein release from chromatin.
Centrifugation protocol: Use differential centrifugation:
Low-speed (1,000g, 10 min) to pellet intact nuclei
High-speed (16,000g, 15 min) to clarify nuclear lysate
Sample Preparation for Electrophoresis:
Denaturing conditions: Heat samples at 95°C for 5 minutes in Laemmli buffer with 100mM DTT.
Loading amount optimization: Test protein gradients (10-50μg) to determine minimal amount needed for detection.
Gel concentration: Use 8-10% acrylamide gels for optimal resolution of At3g16590 (molecular weight determination based on sequence analysis).
This optimized protocol significantly improves detection sensitivity compared to standard plant protein extraction methods, particularly for nuclear transcriptional regulators like At3g16590 .
Analyzing ChIP-seq data for At3g16590 binding sites requires a systematic bioinformatics approach to identify genuine binding regions and connect them to biological function:
Primary Analysis Pipeline:
Quality control of sequencing data:
Use FastQC to assess read quality, adapter contamination, and GC bias
Filter low-quality reads and trim adapters using Trimmomatic or similar tools
Aim for >20 million uniquely mapped reads for sufficient coverage
Read alignment to reference genome:
Align to the appropriate Arabidopsis thaliana reference genome (TAIR10)
Use Bowtie2 or BWA with parameters optimized for short reads
Filter for uniquely mapped reads with MAPQ score >30
Peak calling:
Use MACS2 with parameters: --gsize 135000000 --qvalue 0.05 --keep-dup auto
Call peaks against input DNA control and IgG control separately
Consider peaks found in both comparisons as high-confidence peaks
Replicate analysis:
Secondary Analysis:
Peak annotation:
Classify peaks by genomic features (promoters, UTRs, exons, introns, intergenic)
Identify distance to nearest transcription start sites
Associate peaks with genes using tools like ChIPseeker or HOMER
Motif discovery:
Use MEME-ChIP or HOMER to identify enriched DNA motifs
Compare discovered motifs with known transcription factor binding sites
Perform de novo motif discovery in peak regions
Integration with transcriptomic data:
Functional Analysis:
Gene Ontology enrichment:
Perform GO term enrichment analysis of target genes
Identify biological processes, molecular functions, and cellular compartments
Use tools like agriGO specifically optimized for plant ontologies
Pathway analysis:
Map targets to KEGG or Plant Reactome pathways
Identify enriched metabolic or signaling pathways
Network analysis to identify regulatory hubs
Comparative analysis:
This comprehensive analytical approach will reveal genome-wide binding patterns of At3g16590 and its role in transcriptional regulation within Arabidopsis thaliana .
Troubleshooting inconsistent Western blot results for At3g16590 requires systematic evaluation of each experimental variable:
Sample Preparation Issues:
Protein degradation: At3g16590 may be susceptible to proteolytic degradation.
Solution: Increase protease inhibitor concentration and maintain samples at 4°C
Add fresh inhibitors immediately before use
Minimize freeze-thaw cycles of protein samples
Insufficient extraction: Nuclear proteins often require specialized extraction.
Post-translational modifications: Variable modifications may affect antibody recognition.
Antibody-Related Problems:
Antibody degradation or denaturation:
Solution: Aliquot antibodies to minimize freeze-thaw cycles
Store according to manufacturer specifications
Check expiration dates and proper storage conditions
Suboptimal antibody concentration:
Solution: Perform antibody titration (1:500, 1:1000, 1:2000, 1:5000)
Optimize both primary and secondary antibody concentrations
Consider longer incubation at 4°C (overnight) with more dilute antibody
Blocking inefficiency:
Transfer and Detection Optimization:
Inefficient protein transfer:
Solution: Optimize transfer conditions (time, voltage, buffer composition)
Consider semi-dry vs. wet transfer for different efficiency
Verify transfer efficiency with reversible staining (Ponceau S)
Detection system sensitivity:
Solution: Compare ECL substrates of varying sensitivity
Consider fluorescent secondary antibodies for more quantitative results
Adjust exposure times systematically
Systematic Troubleshooting Table:
Problem | Observation | Possible Cause | Solution |
---|---|---|---|
No signal | Complete absence of bands | Antibody failure or no protein | Test antibody with positive control; verify protein expression |
Weak signal | Faint bands at correct MW | Insufficient protein or antibody | Increase protein loading; optimize antibody concentration |
Multiple bands | Several bands of varying intensity | Cross-reactivity or degradation | Use more specific antibody; improve extraction protocol with protease inhibitors |
Inconsistent replicates | Variable band intensity between experiments | Extraction variability | Standardize extraction protocol; use loading controls for normalization |
High background | Dark membrane with poor contrast | Insufficient blocking or washing | Increase blocking time; add more stringent washing steps |
Document all optimization steps systematically to establish a reliable protocol for At3g16590 detection in your specific experimental system .
Data Collection and Normalization:
Technical replication:
Perform at least three technical replicates for each biological sample
Use identical protein amounts for Western blot analysis
For RT-qPCR, perform reactions in triplicate
Normalization strategies:
For Western blots: Normalize to stable reference proteins (not β-actin which varies in plants)
Use GAPDH, tubulin, or histone H3 as loading controls
Consider using total protein normalization with stain-free gels or Ponceau S
For RT-qPCR: Use multiple reference genes validated for stability
Quantification methods:
For Western blots: Use densitometry software (ImageJ, Image Lab)
For RT-qPCR: Apply 2^(-ΔΔCt) method with efficiency correction
Statistical Analysis Framework:
Testing for normality and homogeneity of variance:
Apply Shapiro-Wilk test for normality
Use Levene's test for homogeneity of variance
Transform data if assumptions are violated (log transformation)
Comparative statistics for different tissues:
For normally distributed data: One-way ANOVA followed by Tukey's HSD
For non-parametric analysis: Kruskal-Wallis followed by Dunn's test
Include p-value correction for multiple comparisons (Bonferroni or FDR)
Correlation analysis:
Pearson correlation coefficient for linear relationships
Spearman's rank correlation for non-parametric data
Calculate confidence intervals for correlation coefficients
Advanced Statistical Approaches:
Linear mixed-effects models:
Account for random effects (e.g., biological replicates)
Incorporate fixed effects (tissue type, developmental stage)
Use R packages like 'lme4' or 'nlme'
Multivariate analysis:
Principal Component Analysis (PCA) to identify patterns across tissues
Hierarchical clustering to group tissues with similar expression patterns
Heatmap visualization with dendrograms
Sample Data Presentation Table:
Tissue Type | Normalized Expression (Mean ± SEM) | Fold Change vs. Leaf | p-value |
---|---|---|---|
Leaf | 1.00 ± 0.08 | - | - |
Root | 1.85 ± 0.12 | 1.85 | <0.001 |
Stem | 0.76 ± 0.09 | 0.76 | 0.042 |
Flower | 2.34 ± 0.18 | 2.34 | <0.001 |
Silique | 1.12 ± 0.11 | 1.12 | 0.375 |
This statistical framework provides robust quantification of At3g16590 expression patterns across tissues while accounting for biological variability and experimental error sources .
Investigating protein-protein interactions (PPIs) between At3g16590 and other components of the SAGA complex requires sophisticated biochemical approaches that preserve native interactions:
Co-Immunoprecipitation (Co-IP) Strategy:
Gentle extraction protocol:
IP optimization:
Pre-clear lysates with Protein A/G beads to reduce background
Use 2-5μg At3g16590 antibody per 500μg protein lysate
Incubate overnight at 4°C with gentle rotation
Include negative controls: IgG control, lysate from knockout plants
Washing conditions:
Implement progressively stringent washes (increasing salt or detergent)
Monitor complex stability across washing conditions
Preserve sample fractions from each wash for troubleshooting
Detection strategy:
Advanced Interaction Analysis Techniques:
Proximity Ligation Assay (PLA):
Visualize protein-protein interactions in situ
Fixed plant cells are incubated with primary antibodies against At3g16590 and interaction partners
Secondary antibodies with attached DNA probes enable amplification if proteins are in proximity (<40nm)
Fluorescent signal indicates interaction in cellular context
Bimolecular Fluorescence Complementation (BiFC):
Clone At3g16590 and potential interactors into BiFC vectors
Express in protoplasts or stable transgenic plants
Reconstituted YFP/GFP fluorescence confirms interaction
Allows visualization of interaction subcellular localization
Tandem Affinity Purification (TAP):
Generate transgenic plants expressing TAP-tagged At3g16590
Perform sequential purification steps to isolate intact complexes
Identify components by mass spectrometry
Quantify relative abundance of interactors
Mass Spectrometry Workflow for Complex Analysis:
Sample preparation:
Perform immunoprecipitation with At3g16590 antibodies
Digest samples with trypsin or LysC proteases
Fractionate peptides using liquid chromatography
MS analysis parameters:
Use nanoLC-MS/MS for high sensitivity
Implement data-dependent acquisition
Consider SWATH-MS for quantitative comparison
Data analysis approach:
This comprehensive approach will reveal the composition and dynamics of At3g16590-containing SAGA complexes in Arabidopsis thaliana and provide insights into their functional roles in transcriptional regulation .
Post-translational modifications (PTMs) of At3g16590 can significantly impact its function as a transcriptional adaptor. Here's a comprehensive approach to studying these modifications:
Identification of Potential Modifications:
In silico prediction:
Use prediction tools (NetPhos, UbPred, SUMOsp) to identify potential modification sites
Analyze protein sequence for conserved modification motifs
Compare with known modifications in yeast and mammalian ADA3 homologs
Global proteomic screening:
Perform immunoprecipitation of At3g16590 followed by LC-MS/MS
Use enrichment techniques for specific modifications:
Phosphorylation: TiO₂ or IMAC enrichment
Ubiquitination: K-ε-GG antibody enrichment
Acetylation: Acetyl-lysine antibody enrichment
Include proteasome inhibitors (MG132) to detect ubiquitination
Validation and Characterization Methods:
Site-specific antibody approach:
Generate antibodies against predicted modification sites
Validate antibody specificity using synthetic modified peptides
Apply in Western blot and immunofluorescence experiments
Genetic approaches:
Generate site-specific mutants (e.g., S→A for phosphorylation, K→R for acetylation/ubiquitination)
Express mutant forms in at3g16590 knockout background
Assess functional consequences through phenotypic analysis
Pharmacological approaches:
Analysis of Modification Dynamics:
Developmental profiling:
Compare modification patterns across developmental stages
Correlate modifications with developmental transitions
Analyze tissue-specific modification patterns
Stress response analysis:
Expose plants to various stresses (drought, heat, pathogens)
Monitor changes in At3g16590 modification state
Correlate modifications with transcriptional responses
Circadian/diurnal regulation:
Sample plants across time-course (every 4 hours for 24-48 hours)
Quantify modification levels at each timepoint
Correlate with gene expression patterns
Functional Impact Assessment:
Chromatin association:
Perform ChIP using antibodies against modified forms
Compare binding profiles of modified vs. unmodified protein
Correlate modifications with target gene expression
Protein interaction changes:
Compare interaction partners of modified vs. unmodified At3g16590
Assess impact on SAGA complex assembly and stability
Identify modification-dependent interactions
Enzymatic activity effects:
These approaches provide a comprehensive framework for studying At3g16590 post-translational modifications and their functional significance in plant development and stress responses.
At3g16590, as a component of the SAGA complex, is intricately involved in histone modification and chromatin remodeling. Here's a methodological framework for investigating these functions:
Chromatin Immunoprecipitation-Based Approaches:
Sequential ChIP (ChIP-reChIP):
ChIP followed by histone modification analysis:
Genome-wide epigenetic profiling:
Comparative ChIP-seq for histone modifications in wild-type vs. at3g16590 mutants
Focus on activating marks (H3K4me3, H3K9ac, H3K14ac, H3K36me3)
Create integrated epigenomic maps to visualize modification changes
Correlate modification changes with transcriptional alterations
In vitro Biochemical Assays:
Histone acetyltransferase (HAT) activity assays:
Chromatin remodeling assays:
Prepare mononucleosomes with positioned nucleosomes
Incubate with immunopurified At3g16590-containing complexes
Analyze nucleosome positioning changes by MNase digestion
Assess accessibility changes using restriction enzyme accessibility
Cell-Based Functional Approaches:
Chromatin accessibility analysis:
Live-cell imaging of chromatin dynamics:
Generate fluorescently tagged At3g16590 constructs
Create reporter lines for visualization of chromatin states
Perform FRAP (Fluorescence Recovery After Photobleaching) to measure dynamics
Analyze co-localization with chromatin marks in real-time
Integrative Data Analysis:
Multi-omics integration approach:
Combine datasets: ChIP-seq, RNA-seq, ATAC-seq, histone PTM mapping
Identify direct vs. indirect effects of At3g16590 activity
Create visual models of At3g16590-dependent chromatin regulation
Generate testable hypotheses about mechanism of action
Comparison with other SAGA components:
This methodological framework enables comprehensive investigation of At3g16590's role in chromatin regulation, providing insights into how this adaptor protein contributes to transcriptional control in plants through epigenetic mechanisms .